The use of solid-liquid separations is wide-spread and ranges from the large volume separations of minerals from solid-liquid mixtures to the small batch separations of high value products in the biotechnology or pharmaceutical industries. Gravitation, pressure, temperature, centrifugation, and fluid dynamics have been the dominant aspects of conventional solid-liquid separation for the past 50 years. Conventional solid-liquid separation typically consists of two primary steps. In the first step, the solid particulate is separated from the liquid by the application of pressure. The pressure may be applied by means for mechanically applying pressure, which may include a piston, gas pressure, hydrodynamic pressure, gravitational pressure, centrifugal pressure or a combination thereof wherein the liquid passes through a filter and the solid is retained by the filter. One problem encountered is solid loss as a result of solid “breaking through”, i.e. passing through, the filter. An even more serious problem is that the mechanical separation step does not result in a complete separation. This necessitates the second step, a thermal drying process.
The thermal drying process is very much less energy efficient, a factor of over 100-200 times less energy efficient, than the mechanical step. Since enormous volumes of materials are processed each year, more efficient mechanical solid-liquid separations will result in dramatic reductions in overall energy consumption by reducing downstream drying requirements. This would impact energy consumption since thermal drying accounts for a significant portion of total worldwide energy consumption.
Other solid-liquid separations involve the purification of the liquid, e.g. water, from solids.
In some instances, high-gradient magnetic field separation has been used to separate particular magnetic solids from a mixture of solids in a liquid.
An object of the present invention is to provide a filtration apparatus that can provide more efficient and faster solid-liquid separation.